1. Technical Field
This invention relates to dampers, and more particularly, to mechanisms for operating various
usage dampers.
2. Background
In the prior art, a multi-blade damper was positioned in an air duct. The damper could have been for fire, smoke or other air control. The damper was opened by a linkage mechanism attached to, for example, a cable, such that when the cable was pulled, the damper operated (i.e. opened).
To aid in getting the damper to operate, a motor driven fan is used upstream (or downstream) of the damper. A motorized damper operator is used for center pivoted blade dampers and for off-center pivoted blades. It is used to supply air flow in the heating, ventilating and air conditioning system. This motor operator required electrical circuitry not only to operate the center pivoted damper, but more particularly, to operate the damper synchronously with the start-up of the air flow in the air duct. If, for example, the air supply fan came on and the damper didn't open promptly, the duct could be blown apart.
In accordance with my invention, the air conditioning fan itself provides the force means to operate the damper without the need for the separate motor and circuitry.
Furthermore, in cases where the fan does not provide enough air flow power to begin the opening of the damper, it is desirable to provide a means to enhance the airflow initiating means sufficiently to start air flow to operate the damper.